The pulsars with flat PA swings tend to be at high \(\dot{E}\)  as shown in Figure REF . This class of pulsars was identified already in [1]}. They have relatively short periods and hence large polar caps. This makes for a large beam and if \(\alpha \)  is low and the line of sight cuts the beam at high \(|\beta |\)  then the result is a wide profile with a flat PA swing (e.g. PSR J1524–5625, see Figure REF ). Alternatively the emission height could be rather large, this would result in the PA swing leading the profile by a large amount (equation REF ) meaning that we would miss the inflection point entirely.
